1. Field of the Invention:
The present invention is in the field of solid-state, four-region switching devices in general and in particular is directed to a light-activated, four-region, solid-state switching device, of the type known as thyristors, in which the current flows laterally across the device as opposed to vertically through the device.
2. Description of Prior Art:
Light-activated, four-region, solid-state switching devices, thyristors, are well known in the art. Typically, in such devices, current flows vertically through the device and the activating light is introduced parallel to the current flow.
The advantages of introducing light perpendicular to the direction of current flow through the device have been recognized, however, attempts to accomplish this has not produced devices that can be readily produced on a commercial scale with acceptable yields.
Other attempts have been made at introducing light into the thyristor in a direction parallel to the direction of current flow and then causing the light to scatter laterally across the device. This is set forth in U.S. Pat. No. 3,590,344. Such teachings require etching pits in the bottom surface of a silicon wafer and is not satisfactory.